Merge "Make user switching dialog cover top part of the screen as well." into udc-dev am: 72e4b7e0a3 am: c919a7e4fe am: 427d580b1f am: 8bde7a590e

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23639284

Change-Id: Ie35a2a4043f997435f43d5487266764c87fa4169
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>